it means that the crank shaft has to bolts per end cap that hold it to the block
1500--2 bolt, 2500 4 bolt
no cause a 4 bolt main has 2 extra bolts on each main
To tell if your engine is a 2 bolt main or a 4 bolt main. Turn the engine upside down on an engine stand. Next, count the number of bolts on each main bearing cap. if there are two, then its a 2 bolt main. And if there are4, then its a 4 bolt main. This applies to the three center caps. The front and rear are always 2 bolt.
If its a 1/2 ton it will be a 2- bolt main, You can run the engine # if you need to know for sure. But i'd bet its a 2-bolt
If it's the factory engine, then it will be a 2-bolt main engine.
can be both ,i have a 350 010 2bolt main
it is more than likely a two bolt main. i have a 90 1500 and it was a 2 bolt before i changed motors
4 bolt their stronger better lasting
That would be a 4-bolt engine in that truck.
I can't answer your question but I can say that my 260 hp 350 Mercruiser has 2 bolt mains and a 4 bolt rear main. Go figure! So I take it from your question that you also have 2 bolt mains with a 4 bolt rear main.
That would be a 2-bolt main in that truck for sure.
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